Re: Add EXTRA_CFLAGS to configure

On 2015-10-28 11:42:28 -0400, Tom Lane wrote:
> In view of your point (1), I'd be okay with inventing an EXTRA_CFLAGS
> argument that is added to, rather than replacing, the automatically
> computed flags.  But I think that configure must include such flags
> for its own compile runs, else it is not testing the true build
> environment and might get wrong answers.

Ok.

> Is -Werror the only practical case where we need configure to *not* see
> a flag that should otherwise be applied?  If so, maybe we should just
> attack that problem directly and narrowly.  I can think of at least
> two ways:

I can't really any that aren't of the form -Werror or
-Werror=specific-warning. I'm not sure that the latter is particularly
interesting, using -Werror and then -Wno-error=xxx seems like it'd
usually be better.

> 1. Invent a "--with-werror" configure switch that causes -Werror to be
> added to the CFLAGS, but not while running tests that it'd break.
>
> 2. Explicitly filter -Werror out of the user-provided CFLAGS while running
> tests that it'd break.

I think either of these is fine - I've a slight preference for 2)
because we already filter *FLAGS in a bunch of places and it seems a bit
nicer to extend, should another similar case come up.

Do you have a preference?

Andres